Processes for various conversions of low molecular weight olefins are well known in the prior art. Representative of such general conversion processes are U.S. Pat. Nos.: 3,140,249; 3,140,251; 3,140,253; 3,140,322; and 2,972,643.
The conversion of paraffins, olefins and/or naphthenes to aromatics using a ZSM-5 catalyst is disclosed in U.S. Pat. No. 3,756,942. The conversion of olefins to aromatics by use of ZSM-5 and ZSM-8 is disclosed in U.S. Pat. No. 3,760,024. The prior art relating to olefin conversion over ZSM-type catalysts also includes numerous process related patents including: U.S. Pat. No. 3,775,501 (co-feed air with olefins over ZSM-5); U.S. Pat. No. 3,827,968 (ZSM-5 in a two step process); U.S. Pat. No. 3,960,978 (ion-exchange and/or steamed ZSM-5 or ZSM-11); U.S. Pat. No. 4,021,502 (olefin conversion using ZSM-5, ZSM-12, ZSM-18, chabazite and beta zeolite under controlled process conditions); U.S. Pat. No. 4,150,062 (use of co-fed water with olefins over ZSM-5); U.S. Pat. No. 4,227,992 (ethylene/propylene conversion over ZSM-12 employing controlled process conditions).
The above processes employ the aluminosilicates generally known as "ZSM-type" aluminosilicates. (The term "ZSM-type" is generally employed in the literature to denominate the aluminosilicates assigned a "ZSM-n" name where "n" is an integer.) Accordingly, such processes do not relate to a process or processes not employing aluminosilicate molecular sieves.
The use of certain novel non-zeolitic molecular sieves as "polymerization" catalysts to produce high boiling polymerization products is disclosed in copending: U.S. Ser. No. 400,438, filed July 26, 1982; U.S. Ser. No. 480,738, filed Mar. 31, 1983; U.S. Ser. No. 514,334, filed July 15, 1983; and U.S. Ser. No. 514,335, filed July 15, 1983. The interconversion of C.sub.2, C.sub.3 and C.sub.4 olefins using certain non-zeolitic molecular sieves is not disclosed in the aforementioned applications. U.S. Pat. No. 4,310,440, discloses that aluminosphosphates (AlPO.sub.4) may be employed as polymerization catalysts.
A process for the oligomerization olefins to hydrocarbon fuels is disclosed in U.S. Ser. No. 551,881 filed 11-15-83, commonly assigned. The instant invention is to be distinguished from the aforementioned oligomerization process by the selection of specific non-zeolitic molecular sieves for the instant olefin interconversion whereby less than 20 mole percent of the C.sub.2 to C.sub.4 olefins are converted to products containing greater than five carbons.